Air conditioning apparatus



March 29, 1938. M. KALISCHER AIR CONDITIONING APPARATUS Filed May Z51, 1935 5 Sheets-Sheet l FIG- 2.

INVENTOR MILTON KALISCHEFE.

ATTOR Y March 29, 1938. M. KALISCHER AIR CONDITIONING APPARATUS Filed May 31, 1935 I5 Sheets-Sheet 2 INVENTOR a E H C S u A K N O T m M ATTO l NEY March 29, 1938. M. KALISCHER AIR CONDITIONING APPARATUS Filed May 51, 1955 5 Sheets-Sheet Z INVENTOR MILTON KHLJSCH ER.

ATTO EY F"IG.G.

Patented Mar. 29, 1938 UNITED STTES PATEN OFFIG Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a. corporation of Pennsylvania Application May 31, 1935, Serial No. 24,287

3 Claims.

My invention relates to air conditioning apparatus, more particularly to a unit air conditioner having an outdoor or fresh air cc .inection, and it has for an object to provide improved apparatus.

An object of the invention is to provide an outdoor air connection adaptable to window sills of varying heights and depths.

A further object is to prevent admission of cold outdoor air into the room through the return or room air inlet, which may otherwise be produced by the wind blowing a strong air current into the outdoor air connection and backwardly through the return air inlet into the room.

In accordance with a preferred embodiment of my invention, I provide a box-like duct portion on the back of the air conditioner cabinet. Said duct portion is formed with an opening in the top adapted to receive the lower end of a vertically extending duct portion. The latter is so constructed that a portion may be cut off at the lower end in order to provide the desired length thereof, and it has an opening in its rear wall adjacent the top for receiving the forward end of a horizontally extending duct portion. The latter 25 is also constructed so that a portion at the front end may be cut off to provide the desired length, and its rear end is connected with a window or other opening so as to take in air from outdoors.

In order to prevent cold outdoor air from entering the room through the return air inlet, in the winter, I may provide a damper in the outdoor air connection, thereto for operating the same. The thermostat that forms a connection is located in a small passage between the outdoor air stream flowing through the connection and the room, so that room air is normally drawn over the thermostat. However, when the wind blows air into said connection, the direction of flow is reversed so that cold air flows over said thermostat. The latter operates to close said damper in response to the lower temperature imposed thereon.

In its broader aspect, this feature of the invention contemplates an automatic control operative to close the outdoor air damper whenever the wind effects an undesired current of outdoor air.

The above and other objects are affected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a perspective view showing a unit air plied thereto;

and a thermostat connected Fig. 2 is a plan view in section taken on the line IIII of Fig. 3;

Fig. 3 is an end elevation of the duct, parts being shown in section;

Fig. 4 is an end view of the unit air conditioner 5 having the duct applied thereto;

Fig. 4a is a fragmentary view of a detail;

Fig. 5 is a horizontal section, taken on the line V-V of Fig. 6, of a second embodiment;

Fig. 6 is a vertical sectional view taken on the line VIVI of Fig. 5, looking toward the air conditioner;

,Fig. 7 is a horizontal section taken on the line VII-VII of Fig. 6; and

Fig. 8 is a horizontal section taken on the line VIII-VIII of Fig. 6.

Referring to Figs. 1 to 4a in detail, I show a unit air conditioner l0 resting on the floor of a I room ll adjacent a window l2. It includes an outer casing or cabinet l3 having return or room air inlet openings I4 in the end Walls, a discharge opening IS in the top wall and outdoor air openings IS in the rear wall l1. It also includes an inner casing [8 in which there may be disposed. the usual air treating elements, such as heating and humidifying elements for winter use and a cooling element for summer use. The inner casing l8 has inlet openings IS in the end walls thereof, and fans 2| are disposed in said openings to draw in air from the room through the inlets l4 and outdoor air through the openings I6.

To convey fresh air from outdoors to the outlet openings I6, I provide the outdoor air duct constituting the present invention. It includes a box-like duct member 22 attached to the rear wall I! of the cabinet and having openings l6 registering with the openings IS in said rear wall. The duct member 22 may be made of any suitable material, for example, sheet metal. It is formed with an opening 23 in the top wall thereof, as shown in Fig. 3, for connection with a vertically extending duct member 24.

The duct member 24 has an opening 25 in its rear wall 26, adjacent the top thereof, for connection with a horizontally-extending duct member 21, and below said opening 25 it is of a uniform cross-section adapted to fit in the opening 23. It is made of any suitable material that may be readily cut, for example, furniture steel or other suitable material. In manufacture, the duct 50 member 24 is made of a length adapting the duct to a window sill of the maximum height expected to be encountered. To adjust the duct to a lower window sill, a portion of the duct member 24 is cut off from the lower end, and the lower end of the fitting 23 projects beyond the inner surface of I the sash and telescopes within the rear end of the horizontalduct member 21. Louvers 29 are preferably provided in the .fitting 23 for excluding large foreign particles and minimizingentrance of rain. The forward part of the duct member is made of severable material and of uniform cross-section, similarly to the vertical duct member 24, so that a portion thereof may be cut oil to provide the desired horizontal extent of the duct. The duct members 24 and 21 are preferably lined with sound and heat insulating material, such as "Celotex, shown at 30. An important function of this material is to prevent the external surface of the duct, particularly the horizontal portion, being cooled by the outdoor air and condensing moisture from the air in the room in case the latter has been humidified.

A damper or door 3| is provided for each opening l5, being hinged at 32 andbiased to closed position by a spring 33. It is adapted to be opened by a bead chain 34 connected to the transverse armof an angle member 36 fixed to the damper. The bead chain 34 extends through a key-hole slot 31, shown in Fig. 4a, in the adjacent end wall 33 of the duct member 22. The

door 3| may be retained in any desired posi' tion by retaining the bead chain in the narrow part of the slot 31, which part is narrower than the beads in the chain and is thus adapted to receive the part between adjacent beads and to hold the chain. The latter preferably has a ring 39 at its outer end for operating the same.

In the operation of the air conditioner, as-

, suming the doors 3| to be open, the suction of I the fans 2| causes flow of air from the room inwardly through the inlets I4, and also flow of fresh air from outdoors through the, outdoor air ducts and the openings l6, It to the interior of the cabinet II, where it mixes with the return or room air before entering the inner casing through the'openings l3. In the latter it is conditioned-and discharged through the outlet l5 in the top. By moving the position of one or both of the doors 3|, the admission of outdoor air may be varied as desired, the damper being retained in position by latching the bead chain 34 in the recessed or slotted portion of the opening'31.

In the above embodiment, the duct is used to convey fresh outdoor air to be supplied to the room. It may also be used, however, to convey outdoor air to the conditioner for cooling the condenser, and/or for exhausting air from the condenser or from the room.

In the use of the above structure in winter,

it has been found that a strong wind blowing.

into the outdoor air connection causes a current of fresh air through the duct of such force as to counteract the suction efi'ect of the fans and to cause flow of the cold outdoor air outwardly through the return air inlet openings l4 into the room. To avoid such a draft of cold air, the control mechanism shown in Figs. 5 to 8 may be used to close the doors 3|. 4

In this embodiment, a thermostat is provided for each door 3|. The thermostat comprises a bellows 4| disposed adjacent the end wall 33 and enclosed in a casing 42. The bellows contains a volatile fluid providing a pressure increasing with the temperatnre to which the bellows is subjected, which pressure causes the bellows to expand with increase in temperature and vice versa. The end wall 33 has an opening 43 communicating with the casing 42, and the latter has a number of small openings 44 in the top thereof. The bottom of the bellows is fixed through a stem 45 to the bottom of the casing 42, while the top of the bellows has a movable stem 46 extending through the top of the casing. The stem 45 has a; closure disc 41 mounted thereon above the casing for closing the openings 44 upon downward movement, being adapted to seat against a felt ring 41. A chain 48 is connected to the upper end of the stem 45v and extends over a pulley 49, carried by a bracket 5|, to the outer end of an arm 52 fixed to the door 3|.

A bead chain 34 is provided for opening the door 3| by hand, as in the first embodiment, but in this case, the pull on the door is transmitted through a spring 53, in order that the door may be closedby the thermostat against the action of the chain 34. One end of the spring 53 is connected to a bracket 54 fixed on the door 3|, while the other end of the spring- 53 and the end of the chain 34 are connected to the outer end of one arm of an angle member 55. The latter is hinged on the. same hinge pin 55 on which the door 3| is hinged. The other arm of the angle member 55 is adapted to bear against the door in closing direction, being biased in. such direction by a coil spring 51. It is to be understood that the embodiment of Figs. 5 to 8 is in other A respects, the same as that of Figs. 1 to-i.

Assuming first that the bellows 4| is extended, the door 3| may be adjusted to any position by means of the chain 34, which 'may be latched in the recess of the opening'31,-as in the first em-.

bodiment The spring 53 pulls the hinged angle member 55 and the door 3| together, so that they move as a single member and are biased to door closed position by the spring 51 acting through the angle member 55. A pull on the chain 34 acts directly on the angle piece 55, against the action of the spring 51, and the door 3| is brought along under the influence of the spring 53.

'As may 'be noted'from the outline of the ver tical duct member 24 in Fig. 5, the thermostat is located beyond the outdoor air stream normally flowing through the duct member 22, which enters at the top and leaves through the openings IS. The casing 42 in which the thermostat is located, however, is subjected to the suction effect of the fans 2|, and a flow of air fromthe room l is effected through the opening 43, the casing 42, the openings 44, the interior of the duct member 22a, the openings l6 and I5 and the cabinet |3 to the fan 2|. 1 Accordingly,

under normal conditions, the bellows 4| is responv suction effect on the space in the casing 42 and u flows through the openings 44 and 43, and over the bellows 4|, into the room. If the outdoor air is cold, as in the winter, the bellows 4| responds to the cold temperature by contracting and exerting a pull on the chain 48, thereby closing the door 3| and cutting ofi the supply of outdoor air if it is very cold, or partially closing the door to reduce the admission of outdoor air in accordance with the temperature thereof if it is only moderately cold. The bellows 4| has sufficient force to overcome the tension of the spring 53. In this case, the chain 48 pulls the door 3| closed against the tension of the spring 53, so that it is closed regardless of the position at which it may have been manually adjusted. As the bellows 4| contracts, it pulls the closure disc 4'! toward the openings 44 to restrict the admission of cold outdoor air into the room through the casing 42. If the openings 44 are completely closed, the cold air in the casing 42 will slowly mingle with the adjacent room air, so that the bellows will begin to expand again after a short period of time, so that the door may be-reopened if the wind has abated, or if it has not, outdoor air will again fiow through the openings 44 onto the bellows 4| to maintain the same contracted.

It will thus be seen that the admission of cold outdoor air through the outdoor air duct and 'the room inlet openings, during a strong wind blowing into the duct, and the objectionable draft produced in the room thereby, is avoided.

The thermostatic damper control is of still greater advantage on a cold day if the fans are not running. At such time, even a slight breeze into the fresh air duct could readily fiow outwardly through the inlet openings |4 into the room, as there is no fan suction to effect inward flow of room air. Also, if the outdoor air is cold enough, it may freeze the water in the humidifier pipes and spraynozzles in the in- ,ner casing l8, there being no warmer room air art or as are specifically set forth in the appended claims.

What I claim is:

1. Apparatus for air conditioning an enclosure comprising a housing for air treating elements, said housing having a first inlet communicating with said enclosure and a second in,-

to a predetermined maximum force and a low 1 temperature of the current of air entering the second inlet,' whereby admission of fresh air into the enclosure by reverse flow through said first inlet is avoided.

2. A fresh air duct for conveying a stream of fresh air from outdoors to an air conditioning cabinet disposed in an enclosure to be air conditioned, said duct having a damper for controlling flow of air through the duct, means providing a space adapted to communicate with the interior of the duct and with said enclosure so that air from the enclosure may flow through said space to the interior of the duct when the force of said air stream is substantially normal and so that fresh air may flow through said space when the force of said air stream becomes excessive by reason of wind blowing into the duct, a thermostat disposed in said space for controlling said damper, means for manually positioning said damper when the temperature in said space is above a predetermined value, and said thermostat acting to close said damper substantially independently of the actionof said positioning means in response to decrease in temperature in said space below said predetermined value.

3. A fresh air duct for conveying a stream of fresh air from outdoors to an air conditioning cabinet disposed in an enclosure to be air conditioned, said duct having a damper for controlling flow of air through the duct, means providing a space adapted to communicate with the interior of the duct and with said enclosure so that air from the enclosure may flow through said space to the interior of the duct when the force of said air stream is substantially normal and so that fresh air may flow through said space when the force of said air stream becomes excessive by reason of wind blowing into the duct, a thermostat disposed in said space for controlling said damper, means for positioning said damper substantially independently of the action of said thermostat when the temperature in said space is above a predetermined value, and said thermostat acting to close said damper substantially independently of the action 01' said positioning means in response to decrease in temperature in said space below said predetermined value.

LHLTON KALISCHER. 

